Slow yellowish growth under vero 29 3000k/3500k

Halfandhalf

Halfandhalf

Well-Known Member
Pictures - the bottom leaves are darker from when they were in my other tent with 5000k lights. topped a week ago (were yellowing before that too)

I've been trying to figure this out since my last grow, I thought changing nutrients might help a little but my growth under my 3 3000k 90 cri mixed with 3 3500k 80 cri running all together at around 300 watts (goes up to 440) is making my plants seemingly grow very slowly with yellowing growth. My clone is the yellowest one, the plants I planted from seeds are staying more green but still have signs of yellow... I have a 5000k in my other tent and the plants were in there prior to this and were dark green with healthier looking leaves. The leaves in my 3000k/3500k tent are curling slightly. Tried raising to 25 inches and still no change. I'm most concerned about the yellowing and slow growth but I'm guessing it's all related.

So my question is has anyone else encountered this? I've tried more cal mag, more or less grow nutes and nothing really seems to help. Is the 3000k 90 cri inhibiting veg growth? It wouldn't be that hard for me to buy 3 3500k's or 4000k's to replace the 3000k's so I have all 3500k or mixed 3500/4000k. I originally went for the 3000ks because I heard that while it might promote a bit more stretching was still fine full cycle and better for flowering. It just seems like my veg growth is so slow and stressing the plants that it doesn't seem great.

opinions, experiences?
 
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Halfandhalf

Halfandhalf

Well-Known Member
I'm assuming the spectrum is the problem because they weren't showing any signs of yellow under my 5000k veros. No nutrient regiment I have used seems to fix that problem. But I'm not sure which is why I'm asking, especially if others have experience vegging under 3000k 90 cri, I'm just trying to figure this out.
 
M

Mattish

Well-Known Member
after looking online for ya, the only thing i can say it looks similar to is Ph fluctuation.
 
Halfandhalf

Halfandhalf

Well-Known Member
Ya and I've been very careful with pH. Callibrated my pen and left the water for a couple hours to settle just to make sure the ph was stable for the last 3 waterings (5.8 for coco).
 
skoomd

skoomd

Well-Known Member
If anything the 3000k 90 cri would make them grow faster. For 2 reasons

1. All that red promotes the most photosynthetic rate of any other white led

2. All that red promotes elongation, which makes growth appear to be faster.


You're doing something wrong, it's not the lights. If it is, perhaps they're too close or something, but it's not the spectrum,

Flush your medium well. Restart with new nutrient solution. Double check PH.

And do you regularly keep your ph pen calibrated?
 
skoomd

skoomd

Well-Known Member
PSUAGRO. said:
ambient temps?............
Click to expand...
Yeah, what are temps and humidity looking like?

ANC said:
Remember tocheck your plats under normal light.
The COBs can influence how they look in that light.
Often people find that the plants eat up to 25 % more than they normally do, after you put them under LED.
Click to expand...
He already tried more and less nutrients.
 
Halfandhalf

Halfandhalf

Well-Known Member
Well, I tried a few things. Went to the hydro store and bought a bunch of new soil, readygrow aeration coco coir. I took the plants out of their 1 gallon pots, separated the roots from the bottom of the container where they appeared to be concentrated but they looked healthy, white and thick. I put them into the 5 gallon pots with new soil and I'm awaiting results. I watered with a full cal mag 5 ml/g and 7 ml/g pure blend pro grow for about 500 ppm total through the new soil before putting them in, then watered a little more after transplant to get the soil settled. I don't know if this was stupid but I wanted to try something... I also just foliar fed with 1ml/liter of calmag...

About my ph pen, I've been calibrating it to 7.0 and don't have 4.0 but just ordered it. I keep it in a storage solution and clean it with bleach periodically as I've seen fungus growing. Thing is, I just tested the water with a little pH strip and it looks closer to 5.0 than what my pen was showing as 6.1. The 6.0 strip indicator should have been slightly green but it was yellow, the 5.0 indicator color is closer to orange, so I guess not quite 5.0 but definitely not 6.0. So I'm waiting on the 4.0 calibration solution and hoping it really just might be my ph pen being badly calibrated. I'm skeptical it's that far off though since it calibrates perfectly to 7 and reads differences quickly but it's possible?

Also my ambient temps were around 77-79, but I turned down my lights and I'm running 73-75 now. I'd really like to be able to run my lights harder tho... Just thought I'd test if the intensity of light/temps were also a problem.
 
ANC

ANC

Well-Known Member
I try not to soak the soil directly after a transplant. I do like to work with moist substrate though so it doesn't go in quite dry.
I leave it for a day or so before watering to make the roots come out of the plug and to have good access to O2.
 
Randomblame

Randomblame

Well-Known Member
How much wattage per ft² did you use? The yellowing could be bleaching/light stress because of too much intensity. Dimm the light down untill they recover. 15.000lx for small plants and 25.000lx for bigger ones is enough for vegging. A plant getting 35.000lx/500μMol/s/m2 for 20/4h would get >35Mol/d, depending on strain and age it could be already too much. From the 2 pics in your OP alone its hard to say. A few pics under natural light would be better..
 
S

Slinging PAR

Well-Known Member
Even after all the vitriol by the op, clean up of the thread of previous posts with helpful information and being told by others that it isn't the spectrum's fault, the answer is still the same.

Learn to grow.
 
Halfandhalf

Halfandhalf

Well-Known Member
Slinging PAR said:
Even after all the vitriol by the op, clean up of the thread of previous posts with helpful information and being told by others that it isn't the spectrum's fault, the answer is still the same.

Learn to grow.
Click to expand...
I never said I was sure it was the light/spectrum, just that it was definitely playing a part in the condition of my plants vs my other tent. You're the one that was fixated on one aspect of my post and still intent on using insults. I hope it's just some combination of my ph pen being off and intensity being too high. Also don't lie, there were no helpful posts before, it was just you slinging insults. Should change your name to that btw xD..

To the people offering real suggestions, thank you, I'm trying those things out.
 
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poodawg

poodawg

Well-Known Member
i switched from CFL to LED and had to try to fined that sweet spot, now i think this for, mine ,this is yellowing could be bleaching/light stress because of too much intensity.
 
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